Patch "dm cache metadata: fix cmd_read_lock() acquiring write lock" has been added to the 4.4-stable tree

Patch "dm cache metadata: fix cmd_read_lock() acquiring write lock" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    dm cache metadata: fix cmd_read_lock() acquiring write lock

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     dm-cache-metadata-fix-cmd_read_lock-acquiring-write-lock.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 6545b60baaf880b0cd29a5e89dbe745a06027e89 Mon Sep 17 00:00:00 2001
From: Ahmed Samy <f.fallen45@gmail.com>
Date: Sun, 17 Apr 2016 05:37:09 +0000
Subject: dm cache metadata: fix cmd_read_lock() acquiring write lock

From: Ahmed Samy <f.fallen45@gmail.com>

commit 6545b60baaf880b0cd29a5e89dbe745a06027e89 upstream.

Commit 9567366fefdd ("dm cache metadata: fix READ_LOCK macros and
cleanup WRITE_LOCK macros") uses down_write() instead of down_read() in
cmd_read_lock(), yet up_read() is used to release the lock in
READ_UNLOCK().  Fix it.

Fixes: 9567366fefdd ("dm cache metadata: fix READ_LOCK macros and cleanup WRITE_LOCK macros")
Signed-off-by: Ahmed Samy <f.fallen45@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/md/dm-cache-metadata.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -894,9 +894,9 @@ static bool cmd_write_lock(struct dm_cac
 
 static bool cmd_read_lock(struct dm_cache_metadata *cmd)
 {
-	down_write(&cmd->root_lock);
+	down_read(&cmd->root_lock);
 	if (cmd->fail_io) {
-		up_write(&cmd->root_lock);
+		up_read(&cmd->root_lock);
 		return false;
 	}
 	return true;


Patches currently in stable-queue which might be from f.fallen45@gmail.com are

queue-4.4/dm-cache-metadata-fix-cmd_read_lock-acquiring-write-lock.patch